WEST HOLLYWOOD, CA - NOVEMBER 29: Actor John Krasinski attends the DETAILS Hollywood Mavericks Party held at Soho House on November 29, 2012 in West Hollywood. / Jason Merritt Getty Images

by By Bryan Alexander, USA TODAY

by By Bryan Alexander, USA TODAY

Matt Damon plays against his good guy image as a conflicted gas company executive in Promised Land. John Krasinski says his movie co-star is loving the murky character trip.

The two even co-produced Promised Land and wrote the screenplay together based on a story by Dave Eggers.

"One of the best parts of the movie is that Matt had never been able to play this kind of part," Krasinski says, speaking at a Details magazine party honoring Hollywood mavericks Thursday. "He's a a self-loathing, broken and problematic character. We haven't seen this."

Certainly not. The last time Damon went after a plot of land, he was looking to save a zoo in Cameron Crowe's We Bought a Zoo.

But in Promised Land, Damon plays the gas company operative who looks to buy up the rights to a rural Pennsylvania town for natural gas drilling -- which would incorporate the controversial practice of "fracking." Krasinski plays a local environmental activist who tries to rally the community against the proposal. The film directed by Gus Van Sant opens December 28.

"I'm so excited for people to see Matt play this role, which has a lot of faults and a lot of problems," says Krasinski. "His character is trying to figure out his place in life. (Damon) has always wanted to play those parts."

Krasinski too has a good-guy television and screen image, especially with his famous Office character, Jim Halpert. But he's ready to take that conflicted role and even play a villain in the future.

"Playing the nice guy is a lot of fun, there's a lot of worse things than being pinned as the nice guy," says Krasinski "But I'm definitely ready to try on some new hats and one of them would be a villain. That would be great. I'll do it tomorrow."